revert: re PR tree-optimization/78496 (Missed opportunities for jump threading)

2017-05-07  Jeff Law  <law@redhat.com>

	Revert:
	2017-05-06  Jeff Law  <law@redhat.com>
	PR tree-optimization/78496
	* tree-vrp.c (simplify_assert_expr_using_ranges): Remove debugging
	code.

	PR tree-optimization/78496
	* tree-vrp.c (simplify_assert_expr_using_ranges): New function.
	(simplify_stmt_using_ranges): Call it.
	(vrp_dom_walker::before_dom_children): Extract equivalences
	from an ASSERT_EXPR with an equality comparison against a
	constant.

	Revert:
	2017-05-06  Jeff Law  <law@redhat.com>
	PR tree-optimization/78496
	* gcc.dg/tree-ssa/ssa-thread-16.c: New test.
	* gcc.dg/tree-ssa/ssa-thread-17.c: New test.

From-SVN: r247727

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7fb175a..4adb9a8 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2017-05-07  Jeff Law  <law@redhat.com>
+
+       Revert:
+       2017-05-06  Jeff Law  <law@redhat.com>
+       PR tree-optimization/78496
+       * tree-vrp.c (simplify_assert_expr_using_ranges): Remove debugging
+       code.
+
+       PR tree-optimization/78496
+       * tree-vrp.c (simplify_assert_expr_using_ranges): New function.
+       (simplify_stmt_using_ranges): Call it.
+       (vrp_dom_walker::before_dom_children): Extract equivalences
+       from an ASSERT_EXPR with an equality comparison against a
+       constant.
+
 2017-05-06  Jeff Law  <law@redhat.com>
 
        PR tree-optimization/78496

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 42782a6..df971bd 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2017-05-07  Jeff Law  <law@redhat.com>
+
+       Revert:
+       2017-05-06  Jeff Law  <law@redhat.com>
+       PR tree-optimization/78496
+       * gcc.dg/tree-ssa/ssa-thread-16.c: New test.
+       * gcc.dg/tree-ssa/ssa-thread-17.c: New test.
+
 2017-05-06  Jeff Law  <law@redhat.com>
 
        PR tree-optimization/78496

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-16.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-16.c
deleted file mode 100644 (file)
index 78c349c..0000000
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-16.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* { dg-do compile } */ 
-/* { dg-options "-O2 -fdump-tree-vrp1-details" } */
-
-/* We should thread the if (exp == 2) conditional on the
-   the path from inside the if (x) THEN arm.  It is the only
-   jump threading opportunity in this code.  */
-   
-/* { dg-final { scan-tree-dump-times "Threaded" 1 "vrp1" } } */
-
-
-extern void abort (void) __attribute__ ((__nothrow__, __leaf__))
-  __attribute__ ((__noreturn__));
-
-int x;
-
-
-int code;
-void
-do_jump (int exp)
-{
-  switch (code)
-    {
-    case 4:
-      if ((exp) == 1)
-       goto normal;
-      if (x)
-       {
-         if (exp != 0)
-           abort ();
-       }
-      if ((exp) == 2)
-       goto normal;
-    case 3:
-       abort ();
-    }
-  normal:
-      ;
-}

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-17.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-17.c
deleted file mode 100644 (file)
index 692658f..0000000
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-17.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/* { dg-do compile } */ 
-/* { dg-options "-O2 -fdump-tree-vrp1-details" } */
-
-/* We should simplify one ASSERT_EXPR from a relational
-   into an equality test.  */
-/* { dg-final { scan-tree-dump-times "Folded into:\[^\r\n\]*ASSERT_EXPR\*\[^\r\n\]* == 1" 1 "vrp1" } } */
-
-/* And simplification of the ASSERT_EXPR leads to a jump threading opportunity.  */
-/* { dg-final { scan-tree-dump-times "Threaded" 1 "vrp1" } } */
-
-extern void abort (void) __attribute__ ((__nothrow__, __leaf__))
-  __attribute__ ((__noreturn__));
-
-union gimple_statement_d;
-typedef union gimple_statement_d *gimple;
-
-
-
-union gimple_statement_d
-{
-  unsigned num_ops;
-};
-
-void
-gimple_assign_set_rhs_with_ops_1 (int code, gimple stmt, unsigned new_rhs_ops)
-{
-
-  stmt->num_ops = new_rhs_ops + 1;
-  if (stmt->num_ops <= 1)
-    abort ();
-  if (new_rhs_ops > 1)
-    if (stmt->num_ops <= 2)
-      abort ();
-  if (new_rhs_ops > 2)
-      abort ();
-}

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 4d29158..cf50e90 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -9600,42 +9600,6 @@ range_fits_type_p (value_range *vr, unsigned dest_precision, signop dest_sgn)
   return true;
 }
 
-/* Simplify STMT, an ASSERT_EXPR, using ranges.  This is helpful because jump
-   threading looks at the ASSERT_EXPRs.  Collapsing the condition of
-   an ASSERT_EXPR from a relational to an equality test is where most
-   of the benefit occurrs, so that's the only thing we currently do.  */
-
-static bool
-simplify_assert_expr_using_ranges (gimple *stmt)
-{
-  tree cond = TREE_OPERAND (gimple_assign_rhs1 (stmt), 1);
-  tree_code code = TREE_CODE (cond);
-  tree op0 = TREE_OPERAND (cond, 0);
-
-  /* The condition of the ASSERT_EXPR must be a simple relational
-     between an SSA_NAME (with a range) and a constant.  */
-  if (TREE_CODE (op0) != SSA_NAME
-      || !INTEGRAL_TYPE_P (TREE_TYPE (op0)))
-    return false;
-
-  tree op1 = TREE_OPERAND (cond, 1);
-  if (TREE_CODE (op1) != INTEGER_CST)
-    return false;
-
-  value_range *vr = get_value_range (op0);
-  if (!vr || vr->type != VR_RANGE)
-    return false;
-
-  tree res = test_for_singularity (code, op0, op1, vr);
-  if (res)
-    {
-      TREE_SET_CODE (cond, EQ_EXPR);
-      TREE_OPERAND (cond, 1) = res;
-      return true;
-    }
-  return false;
-}
-
 /* Simplify a conditional using a relational operator to an equality
    test if the range information indicates only one value can satisfy
    the original conditional.  */
@@ -10370,9 +10334,6 @@ simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
        case MAX_EXPR:
          return simplify_min_or_max_using_ranges (gsi, stmt);
 
-       case ASSERT_EXPR:
-         return simplify_assert_expr_using_ranges (stmt);
-
        default:
          break;
        }
@@ -10637,18 +10598,6 @@ vrp_dom_walker::before_dom_children (basic_block bb)
        {
          tree rhs1 = gimple_assign_rhs1 (stmt);
          tree cond = TREE_OPERAND (rhs1, 1);
-         tree lhs = gimple_assign_lhs (stmt);
-         m_const_and_copies->record_const_or_copy (lhs, TREE_OPERAND (rhs1, 0));
-
-         if (TREE_CODE (cond) == EQ_EXPR)
-           {
-             tree cond_op0 = TREE_OPERAND (cond, 0);
-             tree cond_op1 = TREE_OPERAND (cond, 1);
-             if (TREE_CODE (cond_op0) == SSA_NAME)
-               m_const_and_copies->record_const_or_copy (cond_op0, cond_op1);
-             continue;
-           }
-
          tree inverted = invert_truthvalue (cond);
          vec<cond_equivalence> p;
          p.create (3);
@@ -10656,6 +10605,9 @@ vrp_dom_walker::before_dom_children (basic_block bb)
          for (unsigned int i = 0; i < p.length (); i++)
            m_avail_exprs_stack->record_cond (&p[i]);
 
+         tree lhs = gimple_assign_lhs (stmt);
+         m_const_and_copies->record_const_or_copy (lhs,
+                                                   TREE_OPERAND (rhs1, 0));
          p.release ();
          continue;
        }